lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ipv6: make fragment identifications less predictable

Browse Source 
IPv6 fragment identification generation is way beyond what we use for
IPv4 : It uses a single generator. Its not scalable and allows DOS
attacks.

Now inetpeer is IPv6 aware, we can use it to provide a more secure and
scalable frag ident generator (per destination, instead of system wide)

This patch :
1) defines a new secure_ipv6_id() helper
2) extends inet_getid() to provide 32bit results
3) extends ipv6_select_ident() with a new dest parameter

Reported-by: Fernando Gont <fernando@gont.com.ar>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2011-07-21 21:25:58 -07:00
committed by David S. Miller
parent 21efcfa0ff
commit 87c48fa3b4
7 changed files with 64 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
include/net/ipv6.h
View File

@ -463,17 +463,7 @@ static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_add
return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
}
static __inline__ void ipv6_select_ident(struct frag_hdr *fhdr)
{
static u32 ipv6_fragmentation_id = 1;
static DEFINE_SPINLOCK(ip6_id_lock);
spin_lock_bh(&ip6_id_lock);
fhdr->identification = htonl(ipv6_fragmentation_id);
if (++ipv6_fragmentation_id == 0)
ipv6_fragmentation_id = 1;
spin_unlock_bh(&ip6_id_lock);
}
extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
/*
* Prototypes exported by ipv6